Sealing and position rectifying mechanism for shield supports

ABSTRACT

A shielding and breaking unit for long wall working in coal mines, comprises a plurality of endwise aligned units having interconnected base plates and shielding and breaking units that are articulately interconnected to the base plates and to each other. The shielding and breaking units are vertically swung by means of hydraulic jacks. The various shielding and breaking units are spring-urged into engagement with each other and have working surfaces that slidably overlie each other.

[451 Sept. 24, 1974 [56] References Cited FOREIGN PATENTS ORAPPLICATIONS SEALING AND POSITION RECTIFYING MECHANISM FOR SHIELDSUPPORTS DDDD 5555 mmmm 6666 France................................

Great Britain.t....................

on aa mm rr 66 CG 48 7 6576 9999 "H 5043 200 I487 408 6746 9 c m a F.701 mo mm ao w o a Sn Vmu uH k .mfl t n ah Tt 3% 8 am y a tr aa MMB & r0 t n e V n I 1 5 7 [73] Assignees: Banyaszati Kutato Intezet,

Primary Exaniiner- Den nis LfTaylor Attorney, Agent, or FirmYoung &Thompson Budapest; Varpalotai Szenbanyak, Varpalota; Orszagos ignedunits having interconnected base plates and shielding and breaking unitsthat are articulatel Banyagepgyarto Vallalat, Budapest, all of, Hungary;part interest to each ABSTRACT [22] Filed: Mar. 6, 1972 A shielding andbreaking unit for long wall working in 1 pp NO 232 101 coal mines,comprises a plurality of endwise al y interconnected to the base platesand to each other. The shielding and g by means of hyg and breakingunits are spring-urged into engagement with each other and U.S. D,breaking units are vertically wun Int.CL............................................ draulic jacks The variousShieldin [58] Field of Search................ 61/45 D; 91/170 MP;

299/311 33; 248/ 35 7 have working surfaces that slidably overlie eachother.

1 Claim, 5 Drawing Figures m u n u a u PAIENTEnssmlsn SIEU3I5 om Q Q NPm 9 s VIII/IIIIIA IIIIIIIIIA at right angles to the face, the wasteshield fixed with a releasable joint on the waste side, and the breakingshield which is attached at the waste shield end protuding from the baseplate and can be swivelled around an embedded shaft and is supported ata height required by the hydraulic legs resting on the base plate. Thereis a canopy or roof shield tiltable at the cantilevered end of thebreaking shield. The canopy is designed for supporting the roof whileextracting the longwall face and enabling a propless face. A conveyor,eg a chain conveyor parallel to the face is mounted in a cradle at thecoal face side extension of the base plate. When using a shield supportat the working face as a result of the smaller or greater undulations ofroof and floor the gaps between the shield units are never geometricallyparallel neither in vertical, nor in horizontal section. l.e. in orderto assure gap sealing there is needed'a structural solution for thesuspension of the gap sealing plates enabling the angle deflection ofplates both in a vertical and in a horizontal plane while the plateslies on each other. For that purpose gap sealing plates are used at thebreaking shield and waste shield and in certain cases on the canopy tooboth on the waste and roof sides.

The gap sealing plates are attached on the roof and waste sides of theshield units to the canopy, the breaking shield and waste shield of theshield unit being supported in coaxial guiding tubes. In known devicesthe supporting is carried out by springs. These known solutions have thedisadvantage of the impossibility of rectifying the position of theshield units in relation to the face. On uneven floor also the gapsealing does not prove to be reliable because the gap sealing plate cannot follow the displacement of the shield units.

The object of the invention is to develop a sealing and positionrectifying or aligning mechanism for the shield supports used in miningensuring the complete gap sealing for undulating floor, simultaneouslyenabling the position rectifying or aligning of the shield units asrequired by the face.

Consequently the invention involves a sealing andv position rectifyingor aligning mechanism for shield "supports used in the mining havingplates sealing, clos- The main point of the invention is that in thedirection of the symmetry axis of the coaxial guiding tubes belonging toeach gap sealing plate and sliding in each other there is placed a pushbar, one end of which is joined to the piston rod of the hydraulicrectifying cylinder attached turnably to the inside wall of the shieldunit and the other to the limit stop of the gap sealing plate.

A further feature of the invention is that at least one of the hydraulicrectifying cylinders is mounted on'the face side of the shield unit andat least one of those is mounted on the waste side of the shield unitand each hydraulic rectifying cylinder is fitted with special controlmeans.

According to the invention in the coaxial guiding tubes in the directionof the symmetry axes of the guiding tubes there is fitted a coilcompression spring surrounding the outside of the push bar and the coilcompression spring is formed in such way that one end rests on theclosing disc of the guiding tube fixed to the breaking shield and theother end rests on the closing disc of the inside displaceable guidingtube.

Finally according to the invention the closing disc is fitted with anextension containing a bore through which there passes a joint pinplaced into the recess formed on the stop limit plate. By the solutionaccording to the invention the gap sealing plates overlap and cover thegaps left free between the adjacent shield units being displaced duringthe process of longwall extraction hindering the falling through ofrocks. The gap sealing plates are essentially L-shaped steel plates bentor welded. The blades of the plates are displaceable and slidable on thewaste shield, breaking shield and canopy of the shield units by means ofhydraulic rams. The other blade of the L-shaped gap sealing plate isformed as a stop limit and abuts the steel plate side wall of theadjacent shield unit under the effect of the forces mentioned above.Thus the gap sealing plates safeguard the working face protected by theshield support from rocks penetrating from above or from the waste sidewithout hindering at all the free passage in the face.

Further, the gap sealing plates laterally rectify the position of theshield unit line being especially important for flat undulous seams whenthe shield units can slide in relation to each other. This sliding ishindered or at least reduced by the limit stops pressed to the sidewalls. According to our invention the rectification of the lateraldisplacements of shield units is carried out by means of the hydraulicrectifying cylinders or rams joined to the gap sealing plates.

The combination of the gap sealing means and rectifying cylindersaccording to our invention has the advantage that the rectifyingcylinders are in a protected place remaining undamaged by falling rockand enabling the undisturbed passage in both directions of the workingface. By means of the gap sealing plates the rectifying cylinders joinslidably to the adjacent shield units thus preventing damage to therectifying cylinders caused by lateral displacement.

Our invention has the further advantage that the gap sealing between theadjacent shield units and the position rectification of the shield unitsis attained by combining the sealing and rectifying mechanisms, withsimple means suitable for the conditions in mines.

The invention is described by means of a detailed example on the basisof the drawings, in which:

FIG. 1 is a side view of the shield support.

' FIG. 2 is a section along line lI-ll of the shield support shown inFIG. 1.1

FIG. 3 is a cross section along line III-Ill of the breaking shield ofthe unit of shield support shown in FIG. 1

FIG. 4 is a schematic plan view of the shield units of the shieldsupport shown in FIG. 1.

FIG. is a perspective view of apparatus of the invention.

The breaking shield l of the shield units made of steel plates of theshield support shown in the Figures is adjustably supported with thehydraulic legs 3 resting on the base plate 2. The gaps 4 between theadjacent shield units are covered by L-shaped gap sealing plates 5. Theupper blades of the gap sealing plate 5 following the form of thebreaking shield 1 are attached slidably on its upper surface 6. Thelower blades of plates 5 sealing the gaps as shown in FIG. 3 are formedas limit stops 7 bearing against the side walls 8 of the adjacent shieldunits by means of the coil compression springs 9 with great force. Thesprings 9 are set in the way shown in FIG. 3 in the coaxial guidingtubes 10 and 11 sliding one in the other so that one end of the spring 9is bearing against the closing disc 12 of the guiding tube 10 stronglyfixed to the breaking shield l and the other end against the closingdisc 13 of the displaceable in- 'side tube 11. The extension 14 of theclosing disc 13 contains a wide bore 15 through which the joint pin 17loosely fits into the hole 16 of the limit stop 7. Thus between thelimit stop 7 and the closing disc 13 of the inside guiding tube 11 therecan be realized an articulated connection for bringing about the playnecessary for covering the irregularly shaped gaps between the middleinclined shield unit and the adjacent shield units.

Each limit stop 7 has at least two springs 9 the points of applicationof which are near the ends of the limit stop 7 on the coal face or wasteside. In the direction of the symmetry axis of the spring 9 there ismounted the push bar 18 one end of which is connected to rod 21 of thepiston of the hydraulic ram 19 jointedly attached to the wall of theshield unit and the other end to the closing disc 13 of the insidedisplaceable guiding tube 11. The hydraulic ram exerts through the pushbar a high pressure on the limit stop 7 enabling the aligning of theshield support parallel to the face.

The gap sealing plate 5 belonging to the canopy A or the waste shield Bof the shield unit is constructed as above. I I 1;

The hydraulic rams 19 are actuated by control means not shown in theFigures. Conforming to the control means position the pistons 20 areseparately or, simultaneously actuated.

Of the three shield units shown in FIG. 4 the left and right ones arefixed between floor and roof, the-middle shield unit havingsimultaneouslyan inclined position compared with the two extreme shieldunits. In this case after loosening the shielduni'tin inclined positionby feeding pressure mediumlinto the hydraulic ram 19 placed nearer tothe lower edge, the ram 19 extends from the left side extreme positionshown in the Figure towards the right side; thus the middle shield unittakes a position parallel to the two extreme ones. After the positionrectifying above while simultaneously operating the two rams 19 thedistance of the middle shield unit from the extreme ones has to beadjusted.

We claim:

1. Scaling and position-rectifying mechanism for mine shield supports,comprising a plurality of shields disposed in side-by-side relationship,base plate means, power means acting between said base plate means andsaid shields for moving said shields vertically relative to said baseplate means, and gap sealing plates disposed between and covering gapsbetween said shields, each said gap sealing plate overlying a saidshield, and means yieldably urging each said gap sealing plate intolaterally abutting sealing contact with a said shield adjacent theshield said plate overlies, said urging means comprising a push bar thatis pivotally connected to said plate, a hydraulic ram for extending andretracting said push bar, means pivotally mounting said hydraulic ramwithin the shield said plate overlies, a pair of telescoping tubes onesecured to the last-named shield and the other to said pushbar, saidpush bar extending coaxially through said tubes, and a coil compressionspring in said tubes and surrounding said push bar and urging said tubesapart.

1. Sealing and position-rectifying mechanism for mine shield supports,comprising a plurality of shields disposed in side-byside relationship,base plate means, power means acting between said base plate means andsaid shields for moving said shields vertically relative to said baseplate means, and gap sealing plates disposed between and covering gapsbetween said shields, each said gap sealing plate overlying a saidshield, and means yieldably urging each said gap sealing plate intolaterally abutting sealing contact with a said shield adjacent theshield said plate overlies, said urging means comprising a push bar thatis pivotally connected to said plate, a hydraulic ram for extending andretracting saiD push bar, means pivotally mounting said hydraulic ramwithin the shield said plate overlies, a pair of telescoping tubes onesecured to the last-named shield and the other to said push bar, saidpush bar extending coaxially through said tubes, and a coil compressionspring in said tubes and surrounding said push bar and urging said tubesapart.